1. Field of Invention
The present invention relates to a subtitle file loading method of a disc player. More particularly, the present invention relates to a subtitle file loading method of a disc player for loading subtitle files in an efficient way.
2. Description of Related Art
When a disc player plays subtitles, subtitle files are first retrieved from a disc and stored in a memory of the disc player. The subtitle files stored in the memory are further transferred to a subtitle file decoder for decoding. The subtitle file decoder decodes the subtitle files into address signals and display signals. The address signals and the display signals are transferred to a register and a buffer, respectively. The display signals contain the subtitle images to be displayed, while the address signals indicate the addresses of the display signals to be displayed on the displaying device. Afterward, the display signals stored in the buffer are transferred to corresponding addresses on the displaying device according to the address signals in the register.
FIG. 1 is a block diagram illustrating a conventional subtitle file playing system. The subtitle file playing system 100 includes a memory 110, a subtitle file decoder 120, a register 130 and a buffer 140. Subtitle files 102 stored in the disc 101 are first loaded into the memory 110 of subtitle file playing system 100 for temporary storage. Next, the subtitle files 102 are transferred to the subtitle file decoder 120 for decoding into address signals 103 and display signals 104. The display signals 104 contain the subtitle images to be displayed on the displaying device 105, while the address signals 103 indicate the addresses of the display signal 104 to be displayed on the displaying device 105. The address signals 103 and the display signals 104 are further transferred to a register 130 and a buffer 140, correspondingly. The display signals 104 are then transferred to corresponding addresses on the displaying device 105 according to the address signals 103 in the register 130.
FIG. 1 is also a diagram further illustrating how the subtitle files 102 are loaded into the memory 110 from the disc 101 in the prior art. If the memory 110 has the capacity of storing N subtitle files, then those N subtitle files are first loaded sequentially from the disc 101 into the memory 110. Next, the N subtitle files loaded into the memory 110 are further transferred to the subtitle file decoder 120 for sequential decoding. After all N subtitle files in the memory 110 are transferred to the subtitle file decoder 120, the next N subtitle files will be loaded into the memory 110 from the disc 101.
However, the conventional subtitle file loading approach will cause delay or interruption during the subtitle files playing. Since the next N subtitle files must be loaded into the memory from the disc only after the previous N subtitle files have already been transferred to the subtitle file decoder, there is no subtitle file for decoding and subsequent playing while the next N subtitle files are being loaded. Therefore, the playback process of subtitle files would be not smooth by lacking of decoded subtitle files to be played.